Method of making poppet valves



4 1927. Oct w. s. KNUDSEN METHOD OF MAKING POPPET VALVES Filed Anril 21925 2 Sheets-Sheet 1 INVENTOR MLL/HM KHz/055M BY i W %aa%9f ATTORNEYSOct. 4, 1927. 1,644,021

w. s. KNUDSEN METHOD OF MAKING POPPET VALVES Filed April 2, 1925 2Sheets-Sheet 2 INVENTOR MLL/HM 5. fflvupsz/v BY Mr:

ATTORNEYS I Patented a. 4.1921.

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The resent invention relates to a rocess ,Wlth part in'sectiontoillustratethe-metalof makm headed articles, i.- e., art-i esconsisting'o a more or less slender shank or spindle provided at one endwith a head or portion of a greater lateral dimension. It relatesparticularly to the manufacture of poppet valves, bolts, screws, andthe-like. Heretofore m the manufacture of such articles, severalprocesses have been used. In one rocess, the article is machined from abar avingthe diameter of approximately that of the finished head.Another consists in upsetting a head on a piece of the approximatediameter of the shank. The first of these processesproduces articles ofgood quality but at greater expense and waste of material. The secondproduces. an article of good quality as long as the head area does notexceeda certam small increase over the area of the shank. When the ratioof the head area to the shank area exceeds about two and a half, theupset portion is likely to have cracks about its periphery and in allcases will be somewhat spongy. 2 making articles such as poppet valves,this limitation is fatal to the process. On the other hand, in thepresent process, the diiference in area between the'shank and head makeslittle if any difierence and articles produced by it are free fromdefects of this character. The present process is one of extrusion andcomprises, broadly, the production in one operation of a head and shankof the proper sizes, requiring only the finishing step of surfacing bygrinding or otherwise.

In carrying out the process use is made of the apparatus and stepsindicated in the drawings, in which;

Fig. 1 is an elevation of the plunger and die with the die in sectionand the plunger elevated.

Fig. 2 is a similar view with the plunger at the end of the stroke andalso the ejecting device.

' Fig. 3 is a vertical section of the piercing device. Fig. 4 is anelevation of the cutting off mechanism with the cover plate removed.

Fig. 5 is a sectional view of the same on line 5-5 of Fig. 4.

shows a valve made in the 1 hi i he p m.

, valves, apunch pres (not shown) is fit withadie as is .mdicated at 10.'This die is of the form shown, that 'is, it'has a assage through its'lower portion, at 11, of t e size of the valve stem andthe countersunkportion 12 which is formed at its bottom into a matrix for the valvehead as is indicated at 13. P 11 is countersunk from the underside ofthe die as at 14 to permit the stem freedom from contact after passingthe die and countersink 12 is also countersunk as at 15 to permit astrengthening and pilot portion of the male die to enter.

Themale die 18 is carried by the plunger 19 of the press andfits snuglywithin die 10, having its lower end flat or of the configurationdesired, depending upon the arti e beinglproduced.

o rating'the process, metal, such as steel 0 any variety in the form ofround bars or rods of somewhat less diameter than that of the die cavity12, is cut oil in pieces containing sli htly more metal than is to be inthe finish article. The c lindrical slug 20 thus obtained is then heateto'a temperature of about 1500 to 1900 F. and placed in the die asindicated in Fig. 1. It is preferable to lubricate the die before theoperation by ,swabbing with'a high flash oil such as quenching ortempering oil with a flash at about 700 F. a

When the slug 20 has been placed asindicated, the ress is operated tothe position shown in i 2. Using one of the harder is o eration requiresvery high alloy steels, pressure and is ing successfully 'accomplishedwith a press capable of operating at tons in the manufacture of va vesfor the Chevrolet engine.

This operation of the plunger causes extrusion of the metal to the .formindicated in Fig. 2 at 21, i. e., apiece having a head of the desiredform, such as a valve head 22, and a shank or spindle 23. In thisparticular valve the overall len 'h as it comes from the extrusion dieis a ut 6 inches, the diameter of the shank inches, and the of thepress. Passage Per cent.

Silic n 3.60-4.20 Chromium 1.85-2.50 Carbon; .35- .45 Manganese ..25 4052?; 3 2 -1 .under .05

The piece 21 is ejected from the die by steady pressure from below afterlifting the plunger. This is accomplished by the device shown in Fig. 2in which 25 is a cylinder having a closely fitting piston 26 below whichair under compression is admitted through inlet 27.

Piston 26 carries a rod28 which asses through the upper end of the cyliner 25 into a passage 30 through the bed plate 31 registers with thecountersink 14 and die 10 and rod 28 is ada ted to pass into thesepassages, contact wit the lower end of piece 21 and exert suffilpientpressure to force the piece out of the Cylinder 25 is also provided withan air relief opening 33 which relieves the air pressure when the upperend of rod 28 reaches the matrix portion of die 10, and after the airsupply has been cut ofi the piston 26 and rod 28 return by gravity.

Cylinder 25 is also provided with a dram 34 through which any oilrunning down from the die may drain when the piston is in its uppermostposition.

After the piece 21 has been ejected from the die, it is preferablyplaced, while still hot, in a piercing die as indicated in Fig. 3 and aslot 36 formed in the shank 23. In Fig. 3 the die is shown as. in twoparts 37 and 38 between which the shank 23 is clamped, these parts beingprovided with passages 39 and 40. for the piercing punch 41 and punchedout slug 42 respectively.

The still hot .piece 21 is then cut oil to the pro er length in amachine such as is shown in igs. 4 and 5. In this machine, a member 50,serving as a double gear and also as a locater and holder for piece 21,is provided with a longitudinal passage 51 forthe piece 21 andupon itsperiphery with the two gears 52 and 53. Gear 52 is driven from asuitable source of power through rack 54 while gear 53 drives two otherracks 55 and 56.

'These racks 55 and 56 carry respectively a knife 57 and an anvil 58.WVhen power is applied to rack 54 to rotate member 50, the kmfe 57 willmove over the piece 21 and, as the knife edge slopes as shown. will cutoil the end of piece 21, anvil member 58 moving in synchronism with theknife and supporting the piece during the cut.

After the cutting off operation the valve is practically finished exceptfor a surfacing operation.

In the practice of the process as indicated J the head toward the centerand continue withuniformity into the stem. As a result there is producedan article which is very much stronger in tension than those produced inany of the ordinary processes. And while wear is taken laterally of thefibrous structure the greatest stresses are longitudinal of the fibresin such articles as valves. 1n the case of bolts and the like, tensilestrength is usuall the most im ortant characteristic.

It s ould be noted that the invention is not to be limited to the use ofthe particular form of die shown nor to the specific composition ofsteel mentioned as these may ofcourse be varied. In the case of thesteel, the composition mentioned is very hard and diificult to work andit is obvious that softer steels are to be included in the terminologyof the claims. The dimensions of the diameter of the head, and of thestem, and the overall length as hereinbefore set forth are given by wayof example, and may be considerably variedto suit the needs ofmanufacture.

I claim:

1. The process of making a valve having a stem and a head consisting inpreparin a die having a recess shaped to form a va ve seat and anopening from the recess, reparing a blank of steel but slightly sma lerthan the recess in the die,and extruding a portion of the blank throughthe opening to form a valve stem and leaving in the recess a shapedhead.

2. The process of manufacturing a valve which com rises heating aferrous slug to the require temperature, partly extruding it from a dieto form, without substantial u setting, a head in said die ofsubstantial y the finished diameter of the valve head, andsimultaneously extruding a stem for the .valve.

a headed article, valve for v portion and I dimension not greatly inexcess of that of the slug and of substantially the diameter of thefinished valve headand a communicating passage of a diameter not lessthan the finished stem of the valve, pressin said slu in said die toform an article havm a head in said cavity of substantially the nisheddiameter of the valve and to extrude a stem through the passa e,removing said article from the die and thereafter performing one or moreoperations upon the pressed article to produce a finished valve.

5. The process of manufacturing a valve which comprises bringing aferrous slug to a suitable temperature, p acing said slug in a diehaving a cavity with a transverse dimension not greatly in excess ofthat of the slug and of substantially the diameter of the finished valvehead and a communicating assage of a diameter not less than the finishedstem of the valve, pressing said slug in said die by means of a plungerhaving a transverse dimension but sli htly less than the transversedimension 0 the cavity to form an article having a head in said cavityof substantially the finished diameter of the valve head and to extrudea stem throu h the passa removing said article from t e die and ereafterperforming one or more operations upon the pressed article to produce afinished valve.

6. The process of making a valve comprising compressing a heatedmetallic slug in a die having a cavity to form a valve head and apassage, for forming a stem by extrusion, the proportion of the slug anddie preventing substantial expansion of the slug, during the operationof extrusion.

7. A valve produced by heating a ferrous slu to the requiredtemperature, partly extru g said slug from a die to form, withoutsubstantial upsetting, a head in and die of substantially the finisheddiameter of the valve head and simultaneously extruding a stem for thevalve.

In testimony whereof I aflix my signature.

WILLIAM S. KNUDSEN.

